bbb bbm bbo bbr bbw bmb bmm bmo bmr bmw bob bom boo bor bow brb brm bro brr brw bwb bwo bwr m-o m-r m-w mbb mbm mbo mbr mbw mmb mmm mmo mmr mmw mob mom moo mor mow mrb mrm mro mrr mrw mwb mwm mwo mwr mww ob- obb obm obo obr obw om- omb omm omo omr omw oo- oob oom ooo oor oow or- orb orm oro orr owb owm owo oww rbb rbm rbo rbr rbw rmb rmm rmo rmr rob rom roo ror row rrb rrm rrr rwb rwm rwr wbb wbo wbr wbw wm- wmb wmm wmo wmr wob wom woo wor wow wr- wrm wro wrr wrw wwm wwo www